bindresvport.c revision 1.2 
1/*
2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3 * unrestricted use provided that this legend is included on all tape
4 * media and as a part of the software program in whole or part.  Users
5 * may copy or modify Sun RPC without charge, but are not authorized
6 * to license or distribute it to anyone else except as part of a product or
7 * program developed by the user.
8 *
9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12 *
13 * Sun RPC is provided with no support and without any obligation on the
14 * part of Sun Microsystems, Inc. to assist in its use, correction,
15 * modification or enhancement.
16 *
17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19 * OR ANY PART THEREOF.
20 *
21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22 * or profits or other special, indirect and consequential damages, even if
23 * Sun has been advised of the possibility of such damages.
24 *
25 * Sun Microsystems, Inc.
26 * 2550 Garcia Avenue
27 * Mountain View, California  94043
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31/*static char *sccsid = "from: @(#)bindresvport.c 1.8 88/02/08 SMI";*/
32/*static char *sccsid = "from: @(#)bindresvport.c	2.2 88/07/29 4.0 RPCSRC";*/
33static char *rcsid = "$Id: bindresvport.c,v 1.2 1994/12/04 01:13:12 cgd Exp $";
34#endif
35
36/*
37 * Copyright (c) 1987 by Sun Microsystems, Inc.
38 */
39
40#include <sys/types.h>
41#include <sys/errno.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44
45/*
46 * Bind a socket to a privileged IP port
47 */
48bindresvport(sd, sin)
49	int sd;
50	struct sockaddr_in *sin;
51{
52	int res;
53	static short port;
54	struct sockaddr_in myaddr;
55	int i;
56
57#define STARTPORT 600
58#define ENDPORT (IPPORT_RESERVED - 1)
59#define NPORTS	(ENDPORT - STARTPORT + 1)
60
61	if (sin == (struct sockaddr_in *)0) {
62		sin = &myaddr;
63		bzero(sin, sizeof (*sin));
64		sin->sin_family = AF_INET;
65	} else if (sin->sin_family != AF_INET) {
66		errno = EPFNOSUPPORT;
67		return (-1);
68	}
69	if (port == 0) {
70		port = (getpid() % NPORTS) + STARTPORT;
71	}
72	res = -1;
73	errno = EADDRINUSE;
74	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
75		sin->sin_port = htons(port++);
76		if (port > ENDPORT) {
77			port = STARTPORT;
78		}
79		res = bind(sd,
80		    (struct sockaddr *)sin, sizeof(struct sockaddr_in));
81	}
82	return (res);
83}
84